This report sets out the positive and negative impacts of improvements in energy efficiency in buildings that could come about through a recast of the Energy Performance Buildings Directive (EPBD). Successive studies have shown that energy efficiency offers many of the most cost-effective options for meeting global emission targets. In many cases, energy efficiency measures have been shown to be ‘negative cost’, meaning that it would be economically advantageous to implement them.

Global warming and environment problems caused by the excessive emission of greenhouse gases (GHGs), along with rapid economic development has attracted the attention of many countries and regions of the world. Reducing GHG emissions is essential to mitigate the threat of global warming. Household carbon (dioxide) emissions have been recognized as one of the most important contributors to climate change, with a significant impact on both the local and global environment, and various policy instruments have been implemented by governments to bring about the reduction.

People spend most of their time inside buildings, and buildings are responsible for approximately one third of total direct and indirect energy-related worldwide carbon emissions. Likewise, buildings in the U.S. account for about 40% of total U.S. energy consumption. Future building development will be driven not only by emerging challenges such as vulnerability to a changing climate and resource scarcity, but also by disruptive innovations and societal changes.

The built environment accounts for approximately forty percent of the total energy consumption in developed countries. Because buildings have a long life, the greatest opportunity for energy reduction in the built environment will come from energy conservation in the existing building stock. An overview of the policy challenges presented by the built environment, with an emphasis on existing facilities, is accompanied by a discussion of specific technologies that may have the potential to reduce energy use.